1. Field of the Invention
The invention relates to a scrubber apparatus. More particularly, the invention relates to a scrubber apparatus for gas abatement.
2. Description of the Related Art
Semiconductor manufacturing processes generate substantial waste gases that need to be abated before discharging in atmosphere. Conventionally, waste gases produced during semiconductor manufacturing processes, such as fluorocarbon or PFC, are processed in a scrubber installed after exhausting pumps. Fluorocarbon is taken as exemplary waste gas in the following description since it is substantially used in semiconductor processes.
With reference to FIG. 1, a schematic view describes a conventional scrubber apparatus. In FIG. 1, waste gases comprising fluorocarbon gases are to be treated by the scrubber apparatus 10. Fluorocarbon gases are delivered through waste gas inlets 12. To decompose fluorocarbon gases, high temperature condition is necessary. Accordingly, combustion with natural gas, such as propane, associated with oxygen, both delivered through respectively incineration gas inlet 16 and oxygen gas inlet 14, is generated inside a divergent cone 18. The gas with byproducts produced during the combustion flows out of the divergent cone 18 through openings 20 into the chamber 22. Cooling means 24, comprising a cooling circuit 26, cools down the gases that are treated in the scrubber 10. The cooling means 24, besides cooling down byproducts generated by the combustion, also enhances the removal of hazardous acid gases such as described hereafter. The byproducts produced during the combustion are processed according to two ways. Hazardous acids are neutralized through a scrubbing liquid 28, which can be typically an alkaline solution. The rest of gases pass up through a scrubber 30, are cooled by the cooling means 24, and pass through a mist eliminator 32 to be finally discharged into atmosphere.
Issues related to the conventional scrubber, such as described above, principally lie in an occurrence of incomplete combustion. Incomplete combustion happens when the scrubber functions in a deficiency mode or when abnormal events occur during the combustion, the deficiency mode can be defined as a non-optimal functioning of the scrubber, which results in a combustion that does not provide sufficient heat to decompose adequately the waste gases. Consequently, secondary pollution may be generated because the scrubber apparatus 10 does not process the byproducts that are produced by the incomplete combustion. Untreated hazardous gases may be thus released into atmosphere and cause environment pollution.
Another drawback of the conventional scrubber apparatus 10 is that a substantial amount of energy must be provided to decompose the fluorocarbon gas constituents. As a result, thermal waste is unfavorably generated during the combustion that, consequently, also necessitates a lot of coolant and refrigeration power to cool down the gases and byproducts issued from the combustion. In other words, the conventional scrubber excessively consumes energy. A solution is thus needed to improve the conventional scrubber and overcome at least the issues and drawbacks described above.